1. Field of the Invention
The present invention relates to respiratory patient interface systems, and, in particular, to a respiratory patient interface device including a customizable cushion assembly.
2. Description of the Related Art
There are numerous situations where it is necessary or desirable to deliver a flow of breathing gas non-invasively to the airway of a patient, i.e., without intubating the patient or surgically inserting a tracheal tube in their esophagus. For example, it is known to ventilate a patient using a technique known as non-invasive ventilation. It is also known to deliver continuous positive airway pressure (CPAP) or variable airway pressure, which varies with the patient's respiratory cycle, to treat a medical disorder, such as sleep apnea syndrome, in particular, obstructive sleep apnea (OSA), or congestive heart failure.
Non-invasive ventilation and pressure support therapies involve the placement of a patient interface device including a mask component on the face of a patient. The mask component may be, without limitation, a nasal mask that covers the patient's nose, a nasal cushion that rests beneath the patient's nose (such as a “pillows” style nasal cushion having nasal prongs that are received within the patient's nares or a “cradle” style nasal cushion that rests beneath and covers the patient's nares), a nasal/oral mask that covers the nose and mouth, or a full face or “total” mask that covers the patient's face. The patient interface device interfaces the ventilator or pressure support device with the airway of the patient through tubing, so that a flow of breathing gas can be delivered from the pressure/flow generating device to the airway of the patient. It is known to maintain such devices on the face of a wearer by a headgear assembly having one or more straps adapted to fit over/around the patient's head.
Nasal/oral masks, for example, typically include a sealing element or cushion member constructed from a single piece of material that can only offer limited adjustment, for example, by changing the pitch of the mask or cushion member. Most of the adjustments are made by manipulating the headgear assembly attachments and/or a forehead arm. However, anatomical features can vary significantly from one individual to the next. Accordingly, there is no way to effectively and efficiently customize the patient interface device, for example, by shaping or reshaping the cushion member or sealing element to provide a customized, enhanced fit for the patient.